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Need some help from the auto-rotating monitor experts...

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nitz:

OK, the molex connector idea gave me something to go on, did some reading, and had a look inside my computer. There are some unused molex connectors in there. I see one with a yellow wire, 2 black wires, and (I think) a red wire. I was surprised to see 2 black wires...can I use either one for the ground? Do I need to cut the connector off, or would just sticking some wire into the connector work?

TopJimmyCooks:

I think I tried to interchange the two black grounds but one ground is for the 5V, one is for the 12V.  Just make sure you get 5 or 12v when you complete the circuit with a tester. 

Because i had a small FF case with a wierd power supply on the pc, I used a separate ATX power supply for the motor, cab fan and marquee lights.  However, if I had an ATX power supply for the pc, a spare molex off of that would be plenty to pick up the motor as well.

The 131:1 pololu gearmotor needs between 12v and 18v, 12v works fine.  Nephasth explained how everything is fed through the pololu board, but if you need anything else, post.



Le Chuck:

If one was using one of the LED screens with a Lazy Susan mount I don't see why a center mounted 5v servo wouldn't have the torque to muscle a 90 degree rotation.  You just need to isolate the support of the monitor from the force to move the monitor.  If you have a light monitor I think it is definetly worth a shot.  I'd be more worried about getting it to rotate slowly enough, you don't want the screen picking up momentum and stressing the servo. 

TopJimmyCooks:

This is a wheel on wheel system.  The gear ratio given by the small wheel/tire on the monitor disc allows a tiny motor to be used, hence 12v 1/2A power supply to it.  Direct drive takes more like a windshield wiper motor with associated car amperage (3-4 amps or so?) or an Ond-style costly stepper motor.  Even then, there's still a geartrain.  It keeps the cost way down to use the robotics type motors, controllers, and their well developed software. The speed control can be set from 0 to max in increments ranging from 0 to 1000, so speed control may be finer than with a servo.  The servo with the horsepower and chassis to direct drive an lcd would be big bucks. 

I could see a servo that could do 900 degree rotation and accept a decent sized gear on the output shaft, interfaced with a larger gear on the monitor rotation axis (basically what Ond did) but the gear parts get so costly so quick its hard to be cost effective.  That's why the DNA Dan/Weisshaupt solution is so great, no expensive gears. 

Le Chuck:

I am also a huge fan of the DNA Dan/Weisshaupt way but I definetly am going to explore the world of mid sized servos to direct drive a monitor, worst case scenario is I burn out a $20-$30 servo.  As for mounting if you're using a 3 or 4 inch lazy susan bearing it should be pretty staight forward to center mount the servo securely in the existing bearing support.  I know that Pololu has a beast that can move around 430 ozs at 12v but I don't know what the torque stall is at something like 5v.  

Edit:  Just found this servo that rocks 800 oz at 6vs for only a measely $300  :lol

A bit better:  GWS S04 BBM can move 10kg at the post for the low low energy price of 4.8v.  The cost, under $20.  Totally trying this. 

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